Shock absorber



C. W. SHERMAN ET AL Aug. 7, 1928. Y

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Aug. 7, 1928. 1,679,921

C. W. SHERMAN ET AL SHOCK ABSORBER Filed Feb. 24, 1927 2 Sheets-Sheet 2Iii) Patented Aug. 7, 1928.,

UNITED STATES PATENT OFFICE,

CLIFTON Vif. SHERMAN AND JOSEPH M. HALL, OF HAMILTON, ONTARIQCANADA,.AS-

SGNORS TO HALL DRAFT GEAR CORPORATON, OF BUFFALO, NEW YORK, .A COR-PORATION OF NEVI YORK.

SHOCK ABSORBER.

Application filed February 24, 1927. Serial No. 170,611.

This invention relates more particularly to u shock absorber of thetypecontaining a plurality ot sets ot' intercalated `friction plates,means lor moving' said sets of plates lengthwise relatively to eachother, and mean for pressing' said plates togethertransversely 'lorincreasing" the 'friction Contact between the saine and the resistanceeli'ect while the ot plates are moved longitudinally inward relativelyto each other, this transwu'se pressure being relieved when thelongitudinal inward pressure is relaxed, thus permittingot subsequentlymoving` the sets of friction plates lengthwise outwardly relatively toeach other with comparative freedom.

It has been Jfound in practice that when the plates are madecomparatively thin the same are liable to buckle slightly under veryheavy cndwise pressure.

The object of this invention is to avoid such buckling' and to guide theplates len nth-- wise upon each other and this is accon'iplished byproviding` the plates with longitudinally extending;` corrugations whichnot only guide the plates and sti'l'ien them and enable the same towithstand comparatively heavy endwise pressure but also increase thearea or bearingsurface ot the plates 'for a given width and thusincrease their frictional resist-ance and shock absorbing capacity.

ln the accompany]ng; drawings:

ltigure 1 is a vertical section ot a shock absorber embodying ourimprovements taken on line 1 1, Fig. 2. Y

Figure Q is a horizontal longitudinal sec tion of the same taken on lineFig. 1.

Figure 3 is an end elevation of the shock absorber.

Figure 4 is a vertical transverse section oi the same taken on linel-ll 1. y

Figure 5 is aperspective view ot' one of the friction plaies.

lipgure (i is a perspective view oit' a `group ot intercalated platesembodj-/ingr our invenlion in which no central over solid post isemployed. y

tlii'nilar characters o't reference indicate like parte in the several'figures ofthe drawings.

It is customary im shock absorbers of this type to mount the samelengthwise betweenm ot pulling and pusl'iing or bniiing strains to whichthe car is subjected when couplinpI adjacent cars or when drawing;` atrain of cars. For this purpose these main followers together with theshock absorber between them, are mounted between longitudinal sills lo?10 ot the car frame and the outer sides ol" the followers engage withtransverse stops 11, 11, 12, 12, on these sills.

llt will be assumed that the 'follower 8 is at the liront andthefollower 9 at the rear ot the absorber when the same is installed sothat duringi1 a hurling' action on the shock absorber the frontl'ollowcr 8 will be moved inwardly away from its stops 11, 11 while therear follower 9 will be held stationary, and during a pulling;i actionon the shock absorber the 'trout i''illower 8 will remain at rest whilethe rear tollower 9 is moved inwardly by the load upon the same. i

ln its ;'eneral organization the shock absorber which embodies myimprovements :is constructed as follows:

The numerals 13, 1d represent outer or main thrust heads which engagewith their outer sides against the .inner sides, respectively, of thefront and rear Yfollowers and each oit' which is provided with a central(mening` 15 so that each oi: these heads has the iorni ot iframe. (lnthe opposite sides of the inner edgre ot the central oiieninn ot eachouter thrust head the same has inclined iaces 16, 16, which divergeinwardly, as shown in Fig. 1.

Between the sills arranged a column of `friction plates which includestwo sets of intercalated friction plates 17, 1S, which for conveniencemay be termed liront 4and rear se; the outer parts ot the frontset beingarranged within the central opening; et 'the front outer thrust head andthe rear parts oi' thc friction plates being* arranged within thecentral opening* ot the rear outer thrust head.

Adjacent to the inner sides olz the outer thrust heads are two innerthrust heads or t spri seats (i, 'i' each ot which has a centralopening1 19receiving the adjacent parts of the 'friction plates, andprovided on opposite sides of its central opening` with inclined 'laces20, which diverge outwardly and are preferably arranged opposite theinclined faces 1G ot the outer thrust heads, as shown in 1.

loo

It is. desirable to employ the same number of plates-in both sets andarrange the same symmetrically on opposite sides of the longitudinalcenter of the absorber. To permit of doing this a comparatively thick orheavy longitudinal core, postor friction plate 78 arranged centrallybetween the two sets of side friction plates 17, 18, each set in thisinstance consisting of two side plates Ywhich are comparatively thin.

fverse rib having anfinclined outer face 21 Vengaging`with therespective inclined face 16`of the adjacent outer thrust head ano aninclined inner face 23 engaging with therespective inclined face 2() ofthe adjacent .inner thrust head, so that the outer inclined faces ofeach pair of wedge shoes converge outwardly and the inner inclined facesof the same converge inwardly. Y The numeral 2i represents a main thrustspring which is preferably comparatively heavy and of helical form andsurrounds 'the central parts of the friction plates and the inner endsofthe wedge slices and bears at its opposite ends against the inner sidesof the inner thrust heads. Adjacent to the outer diametrically oppositesides of the main thrust spring are two auxiliary release springs 25which are of helical form and pass with' their end portions through sideopenings in the inner thrust head and bear at their opposite endsagainst the inner sides of the two outer thrust heads, as shown inFig. 1. Y

Undue separat-ion of the outer thrust heads is prevented, when thegearis removed from the car, .by tie rods 27 extending through the releasesprings and inner and outer thrust heads, and provided with inwardlyfacing shoulders 2S bearing against the outer sides of the outer thrustheads.

Upon these tie rods and within the release springsare arranged retainingsleeves 29 which latter float on these rods and prevent these springsfrom buckling but are suiiiclently short so as not to interfere with therequired movementA of the main thrust heads toward and from each other.Y The closing movement of the shock absorber is limited by longitudinalover lsolid or stop rods 3() mounted loosely in side openings 31 ininner thrust heads and each adapted to engagent its opposite ends withthe inner'sides ofthe outer thrust heads.

Each'of'the friction plates has its outer end made wider than the innerend thereof [whereby inwardly facing shoulders 32 are formed on oppositeedges of each of these plates which are adapted to be engaged byoutwardly facing shoulders 33, 34, arranged respectively on the adjacentouter and inner thrust heads.

For the purpose of increasing the stiffness of the side friction plates17, 18, each of these plates is provided with one or more longitudinalcerrugations for example, three of such corrugations, as shown in Fi 1,3, 4c, and 5. In order to permit the central or core friction plate 78to bear uniformly against the side friction plates ou opposite sidesthereof this central plate is provided on its opposite sides withlongitudinal eorrugations 7 9 which conform to those of the adjacentside plates 17, 18 and lit Ythe same. For the same reason the inner orbearing sides of the wedge shoes L1, 5, are provided with longitudinalcorrugations 4:5 which correspond in contour to the corrugations of theside friction plates and interengage therewith, as shown in Figs. 3 and4f.

The length of the side and central friction plates 17, 18 and 78 isslightly less than the space between the followers 8, S) when the latterare in the fully closed position under the maximum pushing or pullingload to which the car may be subjected thereby preventing these platesfrom taking the ov-ersolid load and causing the rods or bars 30 to beexclusively employed for this purpose.

Then the shock absorber is in its fully expanded or released conditionthe front set of side friction plates 17 is pulled forwardly byengagement of the shoulders 32 on the plates with the shoulders 34 ofthe front spring seat 6 and the rear set of side plates 18 is pulledrearwardly by engagement of the shoulders 32 of these plates with theshoulde'rs of the rear spring seat 7, .as snown 1n Fig. 2. IThe centralor core friction plate 78 is shifted to a position midway between thefollowers upon releasing the shock absorber by engagement of theshoulders 34;, 34E of the front and rar spring seats 6, 7 with theshoulders v80, 8O at the front and rear ends of the core plate. therebyensuring an even support for the side friction plates throughout theirlength as the latter are pressed transversely inward by the wedgepressure means.

By thus eorrugating the friction plates and shoes they are not onlymaterially sliil cned and present a greater surface for engagement witheach other to increase the frictional resistance against longitudinalmovement relatively to each other but these eorrugations also serve toguide the plates and shoes upon each other and positively preventlateral displacement so that a. uniform operation of the gear isobtained.

The operation of the shock absorber is :is follo fs:

Preparatory to placing the absorber in its operative position as part ofthe draft rigging between `the front and rear stops of the car sills andconnecting the saine with the coupler yoke or similar actuating means,the springs of the absorber are put under an initial compressiomas shownin Figs. 1 and 2, where the followers are repre sented in the lnaxinuunseparated condition.

If a halting or pulling force is applied to either of the followers, 8,9, su'l'licient to overcome the initial resistance of the draft gearcaused by the initial compression on the release springs 25 bearingdirect on the thrust heads 1 3 and 14 and the frictional resistance setup by the action of the main thrust spring 241- acting inwardly on thewedge shoes 4 and 5, the latter are caused to slide on the outeri'nostfriction plates at both ends of the draft gear until the follow ers 8,9, are brought into engagement with the ends of the side frictionAplates `17 18.

The alli/ance of the moving follower and moving outer thrust head, andthe Wedge action due to the engagement of the inclined faces ofthethrust heads with the outer inclines on the companion wedge shoes causesthe latter to be pressed transversely inwardly thereby` increasing thefrictional engagement of the several intercalated plates, and alsoincreasing the frictional resisting capacity of these plates againstmoving one `set of these plates inwardly relative to the other set. Atthe period of closing the draft gear the compression of the releasesprings 25 is increased as well as the compression of the main or thrustspring 211.

Innnediately after the followers 55,` 9, are forced into., contact withthe ends of the side friction plates 17, 18, the intercalated frictionplates are forced to slide inwardly one set relatively to the other,theset at one end being held statioiniry while the set at the other endis forced toward the stationary set, at which time the resistance to thesliding of the friction plates upon each other absorbs the shock or blowwith increasing` capacity due to theinercasing wedging action set up bycompressing the inain spring 2li. i

When the load on the shock absorber is .relieved to such an extent so asto allow the release sgjnings 25 toforce the outer tl'irust heads 13,lll, apart the action is as` avhich tl the shoulders 32 on the frictionplates. 1he pressure of the inain spring 211 is then divided between awedging action on the wedge slices and a retraetive action on thefriction plates, at which time the release springs tend to force theouter or inain thrust heads 1?), la away from the wedging action of 'thefriction or wedge shoes.

l he shoulders 33 on the niain thrill-it heads 13 and 1d engage theshoulders 32 of the friction plates and the shoulders Sil on the coreplate to arrest farther outward inoyenient of the niain thrust headsafter sullicient outward inoveinent is gained to fully relieve thewedging action, any excess capacity in the release springs 25 beingtrani-iferred to tue friction plates so as to act upon thein in thedirection for assisting in retracting thein to their outer position in.i gear is in release.

lf desired, the central core plate and the friction plates .may be niadeof the saine leiigth as the oversolid rods 30 so that the oversolid loadis taken by the combined resistance of the friction plates, the centralcore and the oversolid rods. lf the central core should be inadeslightly longer than the rods '30 and plates 17" and 153 then this corewill take the oversolid load until its ends have been upset sufficientlyby the battering of the followers to reduce the core in length to equalthe ovcrsolid rods after which the oversolid load 'will be dividedbetween them.

A structure embodying our inyention niay also be organized withoutemploying a central core, as shown in Fig. t), in which the two sets offriction plates 171, 1531 are intercala-ted and adapted to slidelengthwise relatively to one another and each of the plates is providedwith longitudinal corrugations 135 which correspond and lit into thelilte corrugations of adjacent plates.

Vile claiin as our invention:

1. A shock absorber comprising aplurality of sets of intercalatedfriction plates which are corrugated lengthwise and have theircorrugations fitting into one anot r, nieans for moving said plates leiA'1h se relative to each other, and nieans for producing a lateralpressure of said plates against ea'ch other, including shoes infovidedon their inner sides with loi'igitudinal. corrierations engaging withthe corran tions on the eitterior of the oul'erinoi-st frictionplaint-1.

2. A shock abi-iol'1 coinprisii'ig a plurality of sets of interralated,friction plates which are cfffrrugated lciiiglhwise and have tl gationsfitting :into one another, means for moving said plates lengthwiserelative 'to each other, and nii-ans for produc ing a lateral. p ire ofsaid plates againef-it each other, in l ng shoes provided on their Versides with loiigitudiintl corrugations i aging with the corrige, tions`on the essl- Slil lill) teri'or vof t-he outermost friction. plates, andwedge means acting on' said shoes.

3. A shock absorber comprising followers movabletoward 'and from oneanother, a plurality ofintercalated friction plates arranged in a columnbetween said followers and including a central core plato and two setsof side plates or symmetrical members arranged on, oppositeV sides ofthe central plate, said central and side plates being provided withcorresponding lonfitudinal corrugat-ions which engage with each other,and means for producing lateral pressure on said plates. ,v

4. A shocl-r absorber comprising followers movabletowardfand from oneanother, a plurality of intercalated friction plates arranged inacolumnbetween said followers and including a central core plate and twosets of side plates or symmetrical members arranged on opposite sides ofthe central' Y plate, said centralvplate being provided at lits.oppositeends with inwardly facing shoulders, said sideplates beingprovided at :their outer ends with inwardly facing shoulders, and thrustheads provided with outwardly facing shoulders adapted to en- Ill gagethe inwardly facing shoulders of said plates,.and means for producinglateral pressure against said plates.

5. A shock absorber comprising followers movable toward and from oneanother, a plurality of intercalated friction plates arranged in` acolumn between said followers and including' a central core plate andtwo f setsof side plates or symmetrical members arranged on oppositesides of the central p late, said central plate being provided at itsopposite ends with inwardly facing shoulders, ysaid side plates beingprovided at their outer ends with inwardly facing shoulders, thrustheads provided with outwardly facing shoulders adapted to engage 'p theinwardly facing shoulders of said plates,

and means for producing lateral pressure against said plates, includinga spring' resistance.

6. Ashocl; absorber comprising followers `movable toward and from oneanother, a

plurality of intercalated friction plates arranged in a` column betweensaid followers and including a central core plate and two setsof sideplates or symmetrical members arranged on opposite sides of the centralplate,jsaid central plate being provided at its opposite ends withinwardly facing shoulders, said side plates being provided at theirouter ends with inwardly facing shoulders, thrust heads provided withoutwardly facing lshoulders adapted to engage the inwardly facingshoulders of' said plates, outer thrust heads engaging with saidfollowers and havying outwardly facing shoulders engaging with theinwardly facing shoulders of said plates, inner thrust heads havingVoutwardly facing shoulders engaging the inwardly facing shoulders ofsaid plates, releasing springs engaging the outer thrust heads, a mainspring resistance engaging the inner thrust heads, and means forproducing lateral pressure against said plates including said mainspring resistance.

7. A shock absorber comprising followers movable toward and from oneanother, a plurality of intercalated friction plates arranged in acolumn between said followers and including a central core plate and twosets of side plates or symmetrical members arranged on opposite sides ofthe central plate, said central plate being provided at its oppositeends with inwardly facing shoulders, said side plates being provided attheir outer ends with inwardly facing shoulders, thrust heads providedwith outwardly facing shoulders adapted to engage the inwardly facingshoulders of said plates, outer thrust heads engaging with saidfollowers and havng outwardly facing shoulders engaging with theinwardly facing shoulders of said plates, innerthrust heads havingoutwardly facing shoulders engaging the inwardly facing shoulders ofsaid plates, releasing springs engaging the outer thrust heads, a mainspring resistance engaging the inner thrust heads, and means forproducing lateral pressure against said plates, including shoes bearingagainst the oute `most plates and cooperating with said thrust heads andalso including said main spring resistance.

8. shock absorber comprising followers movable toward and from oneanother, a plurality of intercalated friction plates arranged in acolumn between said followers and including a central core plate and twosets of side plates lor symmetrical members arranged on opposite sidesof the central plate, said central plate being` provided at its oppositeends with inwardly facing shoulders, said side plates being provided attheir outer ends with inwardly facing shoulders, thrust heads providedwith outwardly facing shoulders adapted to engage the inwardly facingshoulders of said plates, outer thrust heads engaging with saidfollowers and having outwardly facing shoulders engaging with the inwadly facing shoulders of said plates, inner thrust heads havingout`wardly facing shoulders engaging the inwardly facing shoulders of saidplates, releasing springs engaging the outer thrust heads, a main springresistance engaging the inner thrust heads, and means for producinglateral pressure against said plates, including shoes bearing againstthe outermost plates and co-ojerating with said inner thrust heads andhaving wedging engagement with said outer thrust heads and alsoincluding said main spring resistance.

9. A shock absorber comprising followers movable toward and from oneanother, a

plurality of interealated friction plates arranged in a eoluinn betweensaid followers and .including a central core plate and tWo sets o1 sideplates or symmetrical members arranged on opposite sides ot the Centralplate said central plate being provided at its opposite ends Withinwardly facing shoulders, said side plates beine` provided at theirouter ends with inwardly 'facing shoulders, thrust heads provided withoutwardly *lacing shoulders adapted to engage the inwardly facingshoulders oit said plates, outer thrust heads engaging' with saidfollowers and having outwardly facing shoulders engaging with theinwardly facing shoulders ofsaid plates, inner thrust heads havingoutwardly facing shoulders engaging the inwardly l'aeing shoulders olsaid plates, releasing` springs engaging the outer thrust` heads, -an'iain spring;l resistance engaging the inner thrust heads, and means-for producing lateral pressure against said plates, including shoesbearing against the outermost plates and having; Wedgringr'engagementwith said inner and outer thrust heads and also including,` said niainspring resistance.

ln testimony whereof We hereby aitiic our signatures.

CLIFTON YV. SHERMAN. J @SEPI-l1 M. HALL.

